The present invention relates to a laser machine, in particular for both cutting and welding, comprising a laser head with a nozzle for directing on to the workpiece a laser beam together with a gas jet suitable for the operation being performed (cutting or welding); and a numerical control system for moving the laser head in relation to the workpiece/s along continuous programmable trajectories.
Currently used laser machines of the aforementioned type are known to be used predominantly or exclusively for either cutting (e.g. metal or plastic sheet) or welding. Each of these operations, in fact, requires specific equipment comprising a laser head with a nozzle specially designed for the operation in question and, more importantly, for ensuring the production of an optimum gas jet about the laser beam. When cutting, for example, the tip of the nozzle must be so designed as to direct a fairly high-speed jet of oxidizing gas on to the workpiece, which gas provides for improving vaporization of the material in the cutting area, as well as for shielding the focusing lens on the laser head from the gas produced during cutting. When welding, on the other hand, the tip of the nozzle must be so designed as to produce a fairly low-speed jet of protective gas (argon or nitrogen), for ensuring the static nature of the weld pool and flow conditions between the tip and workpiece are unaffected.
If the same machine is used for both cutting and welding, when switching from one to the other, the machine must be stopped for manually changing the laser head or part of it. This inevitably results in impaired flexibility, high cost and organizational problems, especially when a number of different laser heads must be stored for performing different operations.